Feed rollers are commonly used in crop harvesting machines for guiding the crop from a position in front of the roller to a position rearwardly of the roller. Such rollers are used in many different locations in crop feeding systems and the arrangement described herein is not limited to any particular location of such a crop feeding roller.
However one primary use of such rollers is in that of guiding the crop from a harvesting header into the feeder house of a combine harvester. Such headers can be of the type which simply provide a cutter bar across the front of the header using any suitable cutting technique behind which is located the guide roller which includes an auger flight for transporting the crop material inwardly from the width of the cutter bar to the narrower width of the feeder house.
Other arrangements include a feed draper system so that the crop is transported primarily from the width of the cutter bar inwardly to the narrow width of the feeder house using one or more side drapers which carry the crop to a central feed draper which moves rearwardly toward the feeder house. Arrangements of this type are manufactured by a number of manufactures but primarily by the assignee herein. In the draper header system, the feed roller is therefore much narrower since it is only intended to guide the material into the feeder house rather than the transport the material wholly along the length of the header. In many cases therefore the roller is also of smaller diameter.
In all of these arrangements, the roller generally includes a series of angularly and axially spaced fingers which project through the peripheral wall forming the roller and outwardly from the outer peripheral surface of the roller so as to engage the crop.
The fingers are mounted for rotation around a finger axis which is offset from the roller axis. The fingers are driven in their rotation by their engagement with the peripheral wall of the roller. The offset position of the finger axis thus presents the fingers so that there maximum extend from the peripheral surface of the roller is located at the location where the fingers are intended to engage and grasp the crop and the minimum extent is located at the position where the fingers are intended to release the crop. Thus the fingers generally are at their maximum extent at a position directly forwardly of the roller and the fingers rotate with the roller around the underneath of the roller and are retracted as they move behind the roller to allow the crop to be released to enter into the feeder house to be engaged by the feeder chain of the feeder house. At the position rearward of the roller, the fingers are retracted by the position of the finger axis to locations substantially flush with the surface of the roller to release the crop.
This arrangement is well established, widely used and has been widely successful.
One problem which arises with combine harvesters of this general type either using an auger type header or using a draper type header is that over feeding of the crop material into the feeder house can cause a blockage either at the entry to the feeder house or within the feeder house or even at the rotor of the combine harvester. In has become commonly accepted that the technique for removing such blockages is to reverse the feeder chain within the feeder house and to reverse the direction of drive of the roller so that the crop is reverse fed from the blockage forwardly and discharged onto the ground in front of the header. This arrangement has been found to properly and effectively remove such blockages without the necessity for the operator to leave the cab and carry out manual operations of the crop material.
However in some cases there is a tendency for the crop material to collect in the area in front of the feed roller or to be back fed around the feed roller in a wrapping action. If either of these events occurs, there is a significant risk that the material will become compressed in these areas leading to a blockage which cannot be released by operation of the machine and requires the manual intervention of the operator. Such manual intervention requires vigorous physical activity to cut away compacted wrapped crop material using a knife or other suitable tools.
It is common to provide adjustment of the position of the finger axis over a relatively small distance in the position in front of the roller axis so as to slightly angularly adjust the angular position of the maximum extension of the fingers relative to the roller axis. However this is intended merely to adjust the operation in the feeding direction.
In European No: 0567192 (Boucquez) assigned to New Holland which patent was filed in 1992 and granted in 1996, the patent is directed to the concept of providing an actuator which moves the position of the eccentric crank about which the fingers rotate. The adjustment is therefore effected on the go. It is also discussed that the adjustment can be effected so as to take up a position suitable for the reverse rotation of the roller. The pivotal movement of the finger axis takes place about the axis of the roller.
In U.S. Pat. No. 5,620,083 (Vogelgesang) assigned to Deere the patent refers to the above European patent as prior art and is directed to an arrangement which uses no actuator but instead uses the forces from the crop on the ends of the exposed fingers to tilt the finger shaft to a different position using the wall of the roller as a fulcrum. The pivotal movement of the finger axis takes place about the axis of the roller.